The present invention relates to telecommunications and devices for transmitting analog and digital electrical signals. In particular, the present invention relates to a modular cable system for providing communications to a plurality of workstations, which is easy to install and which reliably transmits data at a high rate.
Communications cabling systems transmit information or data in the form of analog or digital electrical signals to and from various offices or workstations. Such cabling systems communicate between a distribution block or a patch panel located in a computer room or closet and telecommunication devices located at the workstations, including telephones, facsimile machines and computers. These cabling systems typically comprise either a single set of continuous wires or, more recently, a series of modular cable assemblies. The use of modular cable assemblies has become increasingly popular because modular cable assemblies permit moves, adds and changes to the cabling system without requiring that the entire system be rewired. Despite the increasing popularity of modular cable systems, such modular cabling systems have several drawbacks.
One drawback with modular cabling systems is that they can be relatively difficult or confusing for relatively unskilled or inexperienced workers to install properly. This problem can be further exacerbated where the modular cable systems includes what will herein be referred to as Y-cable assemblies, which are a relatively recent development. Each Y-cable assembly includes wiring for multiple offices or workstations and includes three connectors. The Y-cable assemblies are interconnected to one another in series to provide the necessary wiring for the individual offices or workstations. Each Y-cable assembly extracts a unique subset of the wires for use by one particular office or workstation. Because each cable assembly extracts a unique subset of wires for use by a particular office or workstation, it is necessary that the different Y-cable assemblies be distinguished from one another to ensure that (1) the proper subset of wires is extracted for use by each particular office or workstation and that (2) two or more identical cable assemblies are not interconnected along the same series of Y-cable assemblies. Because existing Y-cable assemblies are typically distinguished only by a particular part number stamped on one of the connectors, ensuring that the correct Y-cable assemblies are used is difficult since the randomly assigned part numbers must be memorized or written down. Moreover, performing moves, adds or changes on an existing system is further complicated in that such part numbers are typically stamped on portions of the connectors which are not visible once the cable assemblies are installed. As a result, the installer must either remove each of the Y-cable assemblies from the wall or other structure to identify each Y-cable assembly and its unique set of extracted wires or must locate and read any existing written records of the wiring scheme.
Second, existing modular cable systems often use cables which are capable of communicating at Category 5 or higher performance levels, but the connectors can be a weak point which may limit the overall capabilities of the system. NEXT, or near end cross-talk, is a measure of the amount of signal coupling (or cross-talk) which occurs between different pairs of wires in the cables and the connectors, particularly between each transmit pair and its associated receive pair. Such cross-talk is a source of interference that degrades the ability of the system to transmit or receive signals. As transmission rates increase, near end cross-talk also increases. It has been discovered that terminating the wire pairs at pin positions so as to leave empty (or unused) pins between the wire pairs reduces such cross-talk in the connectors and thus enables higher data transmission speeds. Nevertheless, with the continuing demand for faster and faster data transmission rates, there remains a need for cable assemblies that further reduce cross-talk at higher transmission rates.
The present invention provides a communications cabling system having a plurality of unique cable assemblies configured to be serially connected to one another. Each cable assembly includes a plurality of wires having first and second ends, a first connector having a first plurality of electrical contacts electrically connected to each of the plurality of wires at the first end, a second connector having a second plurality of electrical contacts electrically connected to a first unique subset of the plurality of wires at the second end, a third connector having a third plurality of electrical contacts electrically coupled to a second unique subset of the plurality of wires at the second end, and a unique color indicia corresponding to and associated with each unique cable assembly. The color indicia visually indicates at least one of the first and second unique subsets of wires terminating in the second and third connectors, respectively.
The present invention also provides a communications cabling system adapted for being installed adjacent a first side of a structure having a port communicating with a second side of the structure. The cabling system includes a plurality of unique cable assemblies configured to be serially connected together. Each cable assembly includes a plurality of wires having first and second ends, a first connector having a first plurality of electrical contacts electrically connected to each of the plurality of wires at the first end, a second connector having a second plurality of electrical contacts electrically connected to a first unique subset of the plurality of wires at the second end, and a third connector having a third plurality of electrical contacts electrically connected to a second unique subset of the plurality of wires at the second end. At least one of the first, second and third connectors is configured for being supported proximate the port. The at least one of the first, second and third connectors includes a portion accessible from the second side. The portion has a unique indicia corresponding to and associated with each unique cable assembly. The unique indicia indicates at least one of the first and second unique subsets of wires terminating in the second and third connectors, respectively.
The present invention also provides a modular communications electrical connector including a plurality of electrical contacts. At least two of the plurality of electrical contacts are electrically interconnected and are separated by at least one non-interconnected electrical contact.
The present invention also provides a cross talk reduction device for use with a modular communications electrical connector having a plurality of electrical contacts. The cross talk reduction device includes a body configured for being attached to the connector and an electrically conductive material supported by the body and configured to extend from a first contact to a second non-adjacent contact of the plurality of electrical contacts.
The present invention also provides a method for improving performance in a modular communications electrical cable assembly having a connector with a first plurality of electrical contacts electrically connected to a plurality of wires and a second plurality of electrical contacts interleaved between the first plurality of electrical contacts. The method comprises electrically interconnecting together the second plurality of electrical contacts.
The present invention also provides a method for installing a communications cabling system using a plurality of cable assemblies, wherein each cable assembly includes a first connector, a second connector, a third connector, a first unique set of electrical wires connecting the first connector to the second connector, a second unique set of electrical wires connecting the first connector to the third connector, and a unique color indicia associated with each cable assembly based upon the second unique set of electrical wires connecting the first connector and the third connector. The method includes the steps of selecting at least two cable assemblies to form a set in which no two cable assemblies of the set share the same color, and serially connecting the at least two cable assemblies together in any order.